Bio:A native of the planet Korugar in space sector 1417 (as the Guardians designate space), Sinestro was initially considered to be one of the greatest Green Lanterns, but as the years passed, he became more and more fixated not simply on protecting the magenta-skinned Korugarians, but on preserving order in their society. Eventually he concluded that the best way to accomplish this was to conquer them, and to rule the planet as a dictator.

When Hal Jordan joined the Corps, Sinestro was assigned to be his instructor. Jordan was horrified at the way Sinestro ruled his people like a dictator, though Sinestro maintained that his iron-fisted rule was necessary to protect his people from alien forces. As such, while repelling the alien warlords known as the Khunds from attacking the planet, the Korugarians rebelled. When Jordan called for help from the other Green Lanterns, Sinestro's dictatorship was exposed and he was forced before the Guardians for punishment. Sinestro's Green Lantern Ring was given to Katma Tui, the leader of the rebellion who had felt that Sinestro's "protection" kept his people from growing as a society through contact with other alien races.

-- Punishment and villainy --
The Guardians decided to punish Sinestro by banishing him to the "anti-matter universe", in particular, the alien world of Qward. Their motive for doing so was to humble Sinestro, by exiling him to a world ruled by evil and in particular, beings who hated the Guardians and the Green Lanterns. This would be a major miscalculation, as Sinestro instead was taken in by the Weaponers of Qward. The Weaponers were a group of warrior and scientists who hated the Guardians as much as Sinestro did and the two became allies, with the Weaponers offering to help Sinestro gain revenge on the Green Lantern Corps and the Guardians.

Creating a yellow power ring for him to use, they sent him back to his home universe to seek his revenge. Sinestro quickly became a powerful nemesis toward the Green Lantern Corps, partially due to the fact that their power rings cannot directly affect anything yellow. Despite this, skilled Green Lanterns like Jordan always found ways to defeat him.

Before the Guardians took a leave of absence from their universe to attempt mating with their counterparts the Zamarons, they constructed an inescapable prison for Sinestro and thousands of others on Oa. However, Sinestro's cunning prevailed once again and he managed to free himself through the mental manipulation of the Mad God of Sector 3600. Now wielding nearly unlimited power, Sinestro murdered entire star systems until he was finally subdued by the Green Lantern Corps of Earth. Now guilty of multiple acts of genocide, Sinestro was put on trial again by the assembled membership of the Green Lantern Corps. Finding him guilty, they condemned him to death and executed him, not realizing this activated a failsafe system within the Central Power Battery on Oa that caused it to be destroyed should ever a Korugarian male be killed by a Guardian or their agents (the failsafe was created by the Guardians after their mates, the Zamarons left them to live with Korugarians, a fact that they told no one out of jealousy and shame). Ironically, Sinestro's death then resulted (temporarily at least) in what he sought to achieve in life; the destruction of the Corps. He had also managed to cheat death itself by transferring his consciousness into the Central Power Battery, where he made a startling discovery about the ancient Yellow Impurity within the Green Lantern's light.

The yellow impurity turned out to be a sentient entity known as Parallax and the two merged as Hal Jordan entered the battery to desperately try and save the few remaining Green Lanterns, whose power rings had not been rendered powerless by the death of Sinestro. Jordan ultimately defeated Sinestro, whose spirit was condemned to remain trapped inside the power battery for eternity. But for Sinestro, his was a victory that was greater: not only had he decimated the Green Lantern Corps, but through him, the yellow impurity entity Parallax had successfully infected Hal's mind, setting up Sinestro's ultimate triumph.

-- Guy Gardner --
Guy Gardner, forced to forfeit his Green Lantern ring after a grudge match with Jordan, set out on a quest to regain his power and identity. With the help of Lobo, Gardner acquired the yellow power ring of Sinestro from Oa's Crypt of the Green Lantern Corps. The yellow ring did not use a battery to recharge but actually needed to be used against Green Lanterns to restore power. Gardner found this out by accident when a member of the GLC fought him while he had absolutely no power.

As the yellow ring spoke Sinestro's native language, Guy was unable to communicate with it, although it seemed to understand him to a degree.

Guy only wore the yellow ring for a short while as the character was caught up in the new editorial direction for the Green Lantern franchise that led to the controversial Emerald Twilight storyline in Green Lantern (vol. 3) #48-50 and it was decided to take the yellow ring from Gardner and completely reinvent the character.

-- Ultimate Revenge --
In the meantime, the return of the Guardians resulted in the Corps being re-established, only to be attacked and annihilated by Jordan himself when he was possessed by the Parallax entity, and taking it's name. Driven mad with grief by the destruction of his home city and the apathy of the Guardians towards his plight, the yellow impurity pushed Hal towards a Parallax-induced homicidal rampage that left scores of Green Lanterns dead or maimed as Parallax sought to absorb the Central Power Battery's energies into his being.

Sinestro was then revived by the Guardians and sent to stop Hal only to be murdered by his enemy. But Sinestro's death was not as it appeared, as he would later imply that the being that Jordan killed was a construct made by Parallax and unknowingly extracted from the Central Power Battery.

Hal Jordan promptly finished off the Green Lantern Corps by absorbing the Central Power Battery's energies into himself. How Sinestro escaped remains unknown, but he survived and went into hiding as he watched Hal become what Sinestro had become: a traitor and a murderer reviled by his friends and his allies.

-- Return --
Sinestro eventually revealed the charade when Kyle Rayner discovered the existence of Parallax and revealed it to Green Arrow and the Justice League. Nearly killing the two heroes, Sinestro was stopped by the newly resurrected Hal Jordan, who reclaimed his ring and was purged of Parallax's influence. The two fought to a draw, with Sinestro escaping to the anti-matter universe when his ring was damaged by Hal during the fight.

Sinestro later appeared in the miniseries Villains United, where he captured Lady Quark for the Secret Society of Super-Villains. Sinestro had been a member of the group in the past and played a major role in the Society's massacre of the Freedom Fighters, with Sinestro murdering the second Black Condor early on.

Sinestro also has engaged in other sinister schemes: with the Green Lantern Corps restarted with the return of Hal Jordan, Sinestro has decided to found his own Corps, offering yellow power rings, and a role in the Sinestro Corps, to the most feared and savage warriors of the universe. The size and scope of this new organization has yet to be revealed but stands to be a major threat for the Green Lantern Corps in the near future.

In a recent interview with Geoff Johns, writer of the current Green Lantern series, it was revealed that the Sinestro Corps are actually meant to mirror the GLC, to the minutest of details. Johns said, "The Sinestro Corps [will have] its own Oa-type planet, its own Guardians, [and] its own oath."

-- Sinestro Corps --
Enslaving all the Qwardian Weaponeers, surveilled by Arkillo, a large and muscular vicious alien with the same role of Drill Sergeant held by Kilowog in the GLC, he forced them to continuously build new yellow rings, programmed to breach the barrier between anti-matter and matter universe, find and recruit new warriors.

All Qwardians now sport slave collars, put on them by Sinestro himself to assure their loyalty, and the planet has now a huge yellow "Central Battery", like the Oan one.

Known members, other than the Corps namesake and Arkillo, include: Karu-sil, "the girl next door" from a planet populated by murders and sociopaths; Despotellis, a sentient virus capable of attacking Lanterns from the inside; Bedovian, the sniper of the Corps, capable of taking out a target from three sectors away while living off of the fungus growing on his "hermit crab" like shell.

Recently, the Sinestro Corps tried to recruit Batman, known for being able to instill fear into the hearts of man. Batman rejected the ring however, due to Batman's own willpower and his former exposure to a Green Lantern Corps ring. The ring, seeking a "replacement" was sent to Amon Sur, the disgruntled son of Abin Sur, who was attempting to steal Hal Jordan's ring at the same moment.

#1 - '90 Days, Part I: The Powers that Be'#2 - '90 Days, Part II: Balance of Power'#3 - '90 Days, Part III: Power Play'#4 - '90 Days (Part IV): The Will to Power'#5 - 'The Prince Of Power'#6 - 'The Power And The Glory'